Improvement in bridges



PATENTV- ANDREW J. rosfr', onnunson CITY, NEW JEnsEv;Y

`|Mnnovlalvl'r-:NT IN'BRIDGES.

Specification forming part of Letters Patent N0. 81,111.06, dated August 1868. i

llo all whom t may concern: y

Be it known: that I, ANDREW J. POST, of Hudson City, Hudson eounty,in the State of New Jersey, have invented a certain new and Improved Strut for use in Bridges and analogous structures; and I do hereby declare that the following is a full and exact description thereof. L,

My strut is of iron. The main part -is of wrought-iron, and may be rolled out at very moderate expense. A portion at each end is, by preference, cast-iron. The construction is peculiar, and possesses advantages in strength and in economy of structure over any before known to me.

I will rst describe what I consider the best means of carrying out my invention, and will afterward designate the points whichy I believe to be new therein. l

The accompanying drawings form a part of this specification.

Similar letters of reference `indicate like parts in all the figures.

A A are parallelplates of plane-rolled iron. They are wide in the middle and narrow toward each end. The narrowing may co'rrespond with a parabolical curve, or with any otherwhich calculation or which the fancy of the engineer may dictate. The ends are roundyed, and adapted to receive a transverse pin or bolt, as represented.

B B are curved plates of iron, rolled, each with a stout ange, b, on each edge. They may be curved col`d with little difficulty, and are intended to exactly match each other in thickness, curvature, &c. They are applied between the plates A A, so that the ends of the plates B B are in contact eachwith the other, while their bellies or centers are at a considerable distance from each other. The width of the plates B B, being uniform from end to end, allows of their being produced by rolling without difficulty, and allows the plane plates A A to match fairly against the outer faces of the flanges'b b. The curvature of the plates B B corresponds to the width and contour of the plates A A, though the length is less, so that on riveting the iianges b to the edges of the plates A the edges correspond throughout, being coincident, or nearly so, and form a symmetrical and very stiff and light strut, complete, except vat aud near the ends. To complete the ends, I provide castings (l C1 C2. is exactly equal to the width of the plates B, ,so that they will iit between 'the projecting endsl of the plates A. The width of the parts C'1 C2 is less, to allow for the .thicknessof the ianges b b. w

The parts()l C2 serve as'wings or embracing parts, applying c'loselyfto tlieexterior of the plates B' B at the ends, and riveting or bolting through, to hold them in place in hand-ling and in transportation. It will be observed that the casting C is adapted to accommodate the transverse bolt, which has been already referred to as being received in each end of the strut, and also to accommodate the several diagonal braces or other fastenings which may be required in the bridge. After the strut is in place in the bridge, the strain, being compressive, avoids the necessity for the fastening of the cast-iron to the wroughtiron portion 5 but in putting the bridge together, and in moving the struts about, it is desirable to hold them together with considerable rmness. The bolts or rivets, (indicated by 1),) which hold the wings C1 CZ to the irons B B, accomplish this very eifectually.

The material of the whole or of any portion of my strut may be preserved from oxidizing, or from any other destructive influence, by any of the approved means, such as a coating of zinc, tin, or other metal, galvanizing, japanning, painting, or the like, or by a combination of two or more of thesemeans. The preservative means may be applied upon the outside alone, or on the inside alone, or both. I prefer to coat the several pieces of iron before they are applied together. Thus the joints as well as the outer and inner surfaces will be thoroughly preserved.

'It will be understood that either of the plates i may be adapted, by riveting or otherwise, securing-brackets or the like, to receive any braces or other attachments which may be de sired; also, that holes of various sizes may be judiciously made through the plates without entirely defeating the objects of my invention.

I prefer, for ordinary cases, to have the iron B B of exactly the right width; but in case it shall be desired, for any purpose, to make a The width of these at the endstrut a little wider than the iron has been rolled, the thickness may be made out by introducing pieces between the anges b b and the plates A. The piecesmay be continuous,

lor they may be in the form of washers around the several rivets or screw-bolts. I can even make the strut of double thickness by introducing two of the iron parts B b b on each side-that is to say, I can apply two of the irons B together, edge to edge, and rivet their adjacent flanges b, and then can use two of the compound irons thus produced by placing them7 with their ends together and swelling apart, between the plates A A, as above described. In such case it will be understood that the wings C1 C2 must be correspondingly molded; or a portion should be removed at a subsequent stage to accommodate the flan ges.

It wil1,of course, be understood that the ends of the plates of iron A A maybe secured directly to the adjacent faces on the casting by screws or analogous means, tapped into the casting, or fastening through lugs produced thereon, and secured by nuts, or by riveting, if desired; but I do not consider it generally necessary. I may also remark that the material of the entire strut, or of any portion, may be secured together by brazing, soldering, welding, &c., in cases where the size or uses of the strut render it necessary or desirable. The brazing, Snc., may be depended upon alone, or in combination with the more ordinary means of fastening, such as riveting, screw-bolting, and the like.

Having now fully described my invention, what I claim as new, and desire to secure by Letters Patent, is as follows:

In combination with a wrought-iron strut, the employment of end pieces of cast-iron, fitted into and between the parts of the wroughtiron, and receiving a through-bolt through both the wrought and cast iron parts, all substantially in the manner and for the purposes herein set forth. I

In testimony whereof I have hereunto s'et my name in presence of two subscribing witnesses.

ANDREW J POST.

Titnesses IVM. C. DEY, C. C. Lrvnves. 

